Fused nanostructure material

ABSTRACT

Disclosed herein is a nanostructured material comprising carbon nanotubes fused together to form a three-dimensional structure. Methods of making the nanostructured material are also disclosed. Such methods include a batch type process, as well as multi-step recycling methods or continuous single-step methods. A wide range of articles made from the nanostructured material, including fabrics, ballistic mitigation materials, structural supports, mechanical actuators, heat sink, thermal conductor, and membranes for fluid purification is also disclosed.

This application claims the benefit of domestic priority to U.S.Provisional Patent Application Ser. No. 60/474,925 filed Jun. 3, 2003,which is herein incorporated by reference in its entirety.

The present disclosure relates to a nanostructured material comprisingcarbon nanotubes fused together to form a three-dimensional material,and a method of making such a material.

Most two-dimensional materials, such as webs, sheets, and the like, haveinherent shortcomings to their material properties. While metals andplastic have long been favorites because of their wide range ofversatility, for many applications higher strength, higher conductivity,and overall higher performing materials are needed. While the need forsuch exotic materials used to be confined to high tech applications likespace exploration and electronics, they are becoming increasinglyimportant for mass applications in ballistic mitigation applications(such as bulletproof vests), heat sinks, air conditioning units,computer casings, car bodies, aircraft wings and parts, and many otherapplications that cannot tolerate the high cost of current highperforming materials.

For example, one only need read the daily paper to understand the urgentrequirement for a protective material for addition to lightly orunarmored military vehicles in service through out the world.Combatant's lives are being lost, virtually every day and many of theselosses are directly attributable to the explosive force of buriedmunitions, triggered by remote control, when a vehicle passes over theburied device.

Military requirements call for the creation of new light weight bodyarmor for combatants. New materials are sought for protection ofstructures and building from blast forces. Similarly, air transportrequires blast protection for cargo hold containers transportingfreight, or for fuselage protection transporting people.

Current armor protection materials are either unavailable due to greatdemand for individual body armor, and/or are too heavy or too expensivefor the service vehicles.

Recent advances in materials science and nanotechnology have made thecreation of a new class of materials possible; materials with strengthto weight ratios never before achieved. The carbon nanotube, discoveredin the early 1990's, has been widely touted as the next major moleculefor use in a nanocomposite material. Scientists studying the materialproperties of carbon nanotubes assert that this new nanomolecularmaterial is the strongest material known to man. The enormoustheoretical strength properties of the carbon nanotube have not, priorto the Inventor's work, been realized.

As discussed in “SUPER-TOUGH CARBON-NANOTUBE FIBRES,” Alan B. Dalton etal, Nature, Volume 423, Page 703, 12 Jun. 2003, Nature PublishingCompany, which is herein incorporated by reference, single wall carbonnanotube based composite have demonstrated energy of rupture 20 times ofthat for Kevlar® based composites. Due in part to the much strongerbonding between the nanotubes associated with the inventive process, theenergy of rupture of the inventive material is expected to be greaterthan that previously reported.

Accordingly, creating materials, such as a cloth and composites thatcomprises ultra-strong carbon nanotubes fused together to form a highlycross-linked network would be useful for any application requiring highstrength, high thermal conductivity, electrical conductivity, and otherapplications where carbon nanotubes have shown themselves to be superiormaterials.

Accordingly, the present disclosure relates to a nanostructured materialcomposed of fused carbon nanotubes and methods of making such amaterial. The properties associated with such a material leads to arange of beneficial properties such as ultra-high tensile strength,acceptable flexibility and good thermal conductivity and electricalconductivity.

SUMMARY OF THE INVENTION

The following disclosure describes a nanostructured material comprisingcarbon nanotubes fused together to form a three-dimensional structure.Nanotubes described herein generally have an average diameter in theinclusive range of from 1-60 nm and an average length in the inclusiverange of from 0.1 μm to 250 mm.

As used herein the term “fused,” “fusion,” or any version of the word“fuse” is defined as the bonding of nanotubes at their point or pointsof contact. For example, such bonding can be Carbon-Carbon chemicalbonding including sp³ hybridization or chemical bonding of carbon toother atoms.

In the most general sense, the method of making the nanostructuredmaterial described herein comprises

-   dispersing nanotubes in an appropriate fluid, with or without    surfactants, to form a nanotube aliquot,-   depositing the nanotube aliquot onto a porous substrate in an amount    sufficient to obtain a substantially stable interlocking monolithic    structure, and-   fusing the carbon nanotubes together to form a three dimensional    nanostructure.

In one aspect, the method comprises a multi-step recycling method ofmaking a three-dimensional nanostructure, comprising

-   (1) growing carbon nanotubes in a reactor;-   (2) fusing the grown nanotubes to form a three dimensional    nanostructure;-   (3) performing a catalytic procedure on the three-dimensional    nanostructure;-   (4) repeating (1) to (3) for a time sufficient to achieve a desired    thickness or property for the three-dimensional nanostructure.

In another aspect, the method comprises a continuous method of making athree-dimensional nanostructure material, the method comprising growingcarbon nanotubes, in situ, and fusing the grown carbon nanotubessubstantially simultaneously with the growing process.

DETAILED DESCRIPTION OF THE INVENTION

As stated, the present invention relates to a nanostructured materialcomprising carbon nanotubes fused together to form a three-dimensionalstructure. In one aspect of the present disclosure, the nanostructuredmaterial comprises defective carbon nanotubes chosen from impregnated(which is defined as other atoms or clusters inserted inside ofnanotubes), functionalized (which is defined as bonding atoms orchemical groups to the surface of the nanotubes), doped (which isdefined as the presence of atoms, other than carbon, in the nanotubecrystal lattice), charged (which is defined as the presence ofnon-compensated electrical charge, in or on the surface of the carbonnanotubes), coated (which is defined as a nanotube surrounded by ordecorated with clusters of atoms other than carbon), and irradiated(which is defined as the bombardment of nanotubes with particles orphotons such as x-rays of energy sufficient to cause inelastic change tothe crystal lattice of the nanotube. Such nanotubes may be boundtogether or with other “support” materials. “Nanostructured” refers to astructure on a nano-scale (e.g., one billionth of a meter), such as onthe atomic or molecular level.

“Chosen from” or “selected from” as used herein refers to selection ofindividual components or the combination of two (or more) components.For example, the nanostructured material can comprise carbon nanotubesthat are only one of impregnated, functionalized, doped, charged,coated, and irradiated nanotubes, or a mixture of any or all of thesetypes of nanotubes such as a mixture of different treatments applied tothe nanotubes.

“Nanostructured material” is a material comprising at least one of theabove-mentioned carbon nanotube components. Defective carbon nanotubesare those that contain a lattice distortion in at least one carbon ring.A lattice distortion means any distortion of the crystal lattice ofcarbon nanotube atoms forming the tubular sheet structure. Non-limitingexamples include any displacements of atoms because of inelasticdeformation, or presence of 5 and/or 7 member carbon rings, or chemicalinteraction followed by change in sp² hybridization of carbon atombonds.

Another aspect of the invention is directed to elongated nanotubescomprising carbon, wherein the nanotube is distorted by crystallinedefects, similar to those described above. In this embodiment, thenanotubes are distorted, due to the defects, to a degree that thenanotubes, when treated, have significantly greater chemical activitythat allow the nanotube to react with, or bond to, chemical species thatwould not react with or bond to undistorted and/or untreated nanotubes.

The carbon nanotubes used in the nanostructured material may have ascrolled tubular or non-tubular nano-structure of carbon rings, and maybe single-walled, multi-walled, nanoscrolled or combinations thereof.

The carbon nanotubes having a scrolled tubular or non-tubularnano-structure have a morphology chosen from nanohorns, cylinders,nanospirals, dendrites, spider nanotube structures, Y-junctionnanotubes, and bamboo morphology.

The above described shapes are more particularly defined in M. S.Dresselhaus, G. Dresselhaus, and P. Avouris, eds. Carbon Nanotubes:Synthesis, Structure, Properties, and. Applications, Topics in AppliedPhysics. Vol. 80. 2000, Springer-Verlag; and “A Chemical Route to CarbonNanoscrolls, Lisa M. Viculis, Julia J. Mack, and Richard B. Kaner;Science 28 Feb. 2003; 299, both of which are herein incorporated byreference.

In certain embodiments, the three-dimensional nanostructured materialmay further comprise at least one material chosen from polymers,ceramics, and metals, which may be in a form chosen from fibers, beads,particles, wires, sheets, foils, and combinations thereof.

These materials may be used to support the fabrication of thethree-dimensional structure and may become an integral part of thestructure. Alternatively, these materials may be sacrificial, meaningthat they are removed by subsequent processing, such as a thermal orchemical procedures, to eliminate them from the final structure, whileleaving a stable structure comprised almost entirely of carbonnanotubes. The sacrificial support material is generally used inapplications that do not require the properties of the support material,such as in certain high strength or armor/ballistic applications.

Non-limiting examples of polymers that can be used in the nanostructuredmaterial described herein are chosen from single or multi-componentpolymers including nylon, polyurethane, acrylic, methacrylic,polycarbonate, epoxy, silicone rubbers, natural rubbers, syntheticrubbers, vulcanized rubbers, polystyrene, aramid, polyethylene,ultra-high-molecular weight polyethylene, high-density polyethylene(HDPE), low-density polyethylene (LDPE),poly(p-fenyl-2,6-benzobisoxazol), polypropylene, polychloroprene,polyimide, polyamide, polyacrylonitrile, polyhydroaminoester, polyester(polyethylene terephthalate), polybutylene terephthalate,poly-paraphylene terephtalamide, polyester ester ketene, vitonfluoroelastomer, polytetrafluoroethylene, and polyvinylchloride.

Non-limiting examples of ceramics that can be used in the nanostructuredmaterial described herein include: boron carbide, boron nitride, boronoxide, boron phosphate, beryllium oxide, spinel, garnet, lanthanumfluoride, calcium fluoride, silicon carbide, carbon and its allotropes,silicon oxide, glass, quartz, aluminum oxide, aluminum nitride,zirconium oxide, zirconium carbide, zirconium boride, zirconium nitrite,hafnium boride, thorium oxide, yttrium oxide, magnesium oxide,phosphorus oxide, cordierite, mullite, silicon nitride, ferrite,sapphire, steatite, titanium carbide, titanium nitride, titanium boride,and combinations thereof.

Non-limiting examples of metals that can be used in the nanostructuredmaterial described herein include aluminum, boron, copper, cobalt, gold,platinum, silicon, steel, titanium, rhodium, indium, iron, palladium,germanium, tin, lead, tungsten, niobium, molybdenum, nickel, silver,zirconium, yttrium, and alloys thereof.

In one embodiment, at least one of the previously described polymers,ceramics, and metals are coated on the surface of the carbon nanotubesto form a polymer containing layer, a ceramic containing layer, a metalcontaining layer, or a combination of any or all of these layers. Forexample, in certain ballistic applications the nanostructured materialmay comprise at least one layer of boron carbide.

During the processing of the nanostructured material of one aspect ofthe invention, the resulting structure may comprise 5, 6 and 7-memberedcarbon rings at the intersection of two or more carbon nanotubes. Thesedifferent ring structure can lead to distortions in the carbonnanotubes, which tend to aid in the formation of a self-assemblingnanostructured material

The ability of the nanostructured material to have a a wide-rangingdensity, for example ranging from 1 picogram/cm³ to 20 g/cm³, such as1.25 g/cm³, allows the material to be tailored for a variety ofapplications. Non-limiting examples of articles made from thenanostructured material described herein range from fabrics tostructural supports. Electrical, mechanical and thermal propertiesassociated with the carbon nanotube further allow the nanostructuredmaterials to be used in mechanical actuators, heat sink, thermalconductor, or membranes for fluid purification.

For example, because of the high thermal transfer of carbon nanotubes,e.g., about thirty times the thermal conduction of copper, thermalconductors may be used. Alternatively, the insulating propertiesassociated with this material enables blankets, tents, sleeping bags,clothes, and building materials to be constructed from the materialdescribed herein. The material can be functionalized to be an insulatorby keeping nanotube ends from direct connection. The phonons can notpropagate with in the material. Alternatively, by connecting the endsexcellent thermal transport is achieved. For example, nanotubes canexhibit up to twice the heat conduction of atomically perfect diamond.

Carbon nanotubes, which are typically 7-10,000 times more electricallyconductive than copper, enable materials described herein to be used inconducting or near super-conducting applications.

In addition, the high strength associated with carbon nanotubes, about100 times the tensile strength of steel at ⅙^(th) the weight, allows thenanostructured material described herein to be made into punctureresistance applications, such as projectile bombardment or otherballistic mitigation applications. In particular, the nanostructuredmaterial described herein exhibits excellent blast mitigationproperties, which may be defined in terms of energy adsorbed per unitimpact area as a function of the mass of the affected compositematerial.

In such ballistic mitigation applications, the nanostructured materialcan primarily comprise carbon nanotubes in a composition containingboron carbide. Alternatively, the nanostructured material can compriseat least one layer of carbon nanotubes and at least one material, suchas in an alternating layer configuration with the carbon nanotube layer,chosen from the previously described polymers, ceramics, and metalsfused together to form a three-dimensional structure.

For example, boron carbide is a traditional ceramic generally used forblast mitigation materials. The primary drawback of this material isthat it is brittle. However, by incorporating boron into the outershells of a multiwalled carbon nanotubes, it is possible to produce amaterial that will have the flexibility and strength characteristics ofcarbon nanotubes and the micro hardness of boron carbide.

To simply incorporate boron into carbon nanotube material in the nativeform of powder generally yields non-uniformities. To avoid this problem,the Inventors have found it to be advantageous to treat the nanotubesafter they have been formed into a nanostructured material with boroncarbide to develop a coated or doped nanotubes and said material havinga controlled density and porosity.

The boron treatment can be performed by a variety of methods. Forexample, Chemical Vapor Deposition (CVD) can be used to grow a boroncarbide layer surrounding the carbon nanotubes. Alternatively, a hybridmethod that uses CVD to deposit boron on the carbon nanotube while thematerial is irradiated with an electron beam in a range from 80 keV to1.4 MeV can also be used. In this process, the electron beam providessufficient energy to react the carbon in the outer walls of the nanotubewith the boron to produce boron carbide. Other methods to treat carbonnanotubes with boron carbide include, but are not limited to plasmaspray coating and magnetron sputtering.

In general ballistic cloth is a material in a shape of a cloth that willprotect personal or equipment from projectile impact. For example, aflexible cloth that can be worn by personnel in a hostile environment.Using one of the methods described herein, a ballistic cloth may be madein which carbon nanotubes and at least one material chosen from thepreviously described polymers, ceramics, and metals, are present in anamount sufficient to mitigate blast forces from projectiles orexplosives coming into contact with the ballistic cloth. This type ofmaterial may comprise a component of body armor, vehicle armor,bullet-proof vests, shields, blankets, tents, sleeping bags, cargocontainers, shipping containers, storage boxes and containers, buildingshielding materials, and structural components of vehicles, aircraft,spacecraft, and train cars.

More generally, a fabric made from or comprising the nanostructuredmaterial described herein may comprise a garment or article of clothingto be worn or to cover a person or animal, or to cover a vehicle,aircraft, spacecraft, train car, or generally any equipment or structurewhich may benefit from the mechanical, electrical, and/or thermalproperties associated with the carbon nanotube.

Also described herein are methods of making a three-dimensionalnanostructure. In one embodiment, the method comprises dispersingnanotubes in an appropriate fluid, with or without surfactants, to forma nanotube aliquot,

-   -   depositing the nanotube aliquot onto a porous substrate in an        amount sufficient to obtain a substantially stable interlocking        monolithic structure, and    -   fusing the carbon nanotubes together to form a three dimensional        nanostructure.

As used herein “dispersing” comprises ultrasonication or mechanicalmixing in a blender. An appropriate fluid for dispersing nanotubes maycomprise water, organic solvents, acids, or bases. Non-limiting examplesof appropriate organic solvents include ethanol, isopropanol, methanol,and xylene.

As used herein “surfactant” comprises a molecule with two ends: onehydrophobic end and one hydrophilic end. The surfactant enables thenanotubes to disperse in water. A non-limiting example of such asurfactant that can be used in the method described herein is SDS(sodium dodecylsulfate)

In another embodiment, the nanotube aliquot further comprises a supportmaterial chosen from the previously described polymers, ceramics, andmetals, which may be in a form chosen fibers, beads, particles, wires,sheets, foils, and combinations thereof, and being dispersed with thecarbon nanotubes.

When a support material is used, dispersing generally comprisesultrasonication at a level sufficient to cause ultrasonic bonding of thesupport material alone or with the carbon nanotubes. As stated, thesesupport materials may comprise an integral part of the nanostructuredmaterial, or may be sacrificial.

In addition, fusing is typically performed by irradiative, electrical,chemical, thermal, or mechanical processing, either independently or inconjunction with one another. For example, irradiative processing maycomprise e-beam irradiation, UV radiation, X-ray, and ionizingradiation. Chemical processing may comprise treating the carbonnanotubes with at least one material chosen from acids, bases,carboxyls, peroxides, and amines for a time sufficient to facilitatefusion of the carbon nanotubes with one another. Similarly, chemicalprocessing may comprise photochemical bonding for a time sufficient toobtain chemical cross linking. As used herein, “cross linking” meansthat a chemical bond is formed between two or more nanotubes within thecarbon nanotube nanostructured material.

In one embodiment, fusing comprises heating the nanostructure in an ovenat a temperature below the melting point of the support material. Thisprocess can be performed in vacuum, or in an atmosphere chosen frominert gases or air.

In one non-limiting embodiment, the method further comprises thechemical pr physical vapor deposition of at least one material chosenfrom previously described ceramics, metals, and polymers. During thismethod, deposition comprises the depositing of at least one of thepreviously described polymers, ceramics, and metals near theintersecting points of carbon nanotubes.

When fusing occurs through a mechanical process, it can be done througha method chosen from hydraulic pressing, three roll pressing, mechanicalgrinding. According to a method described herein, the three-dimensionalnanostructured material may be thermally or electrically annealed to addfurther benefits to the structure, such as structural integrity. Forexample, by passing a current through or by creating eddy currentsthrough electromagnetic field emersion one can cause electro migrationin an amount sufficient to fuse nanotubes together, which, depending onthe particular conditions (e.g., field strength, nanotube morphology,etc.) can lead not only to the modification of such defects, but cancause defect creation, elimination or migration.

In addition to the above described method, a multi-step recycling methodmay be used to make a three-dimensional nanostructure. Such a methodcomprises

-   (1) growing carbon nanotubes in a reactor;-   (2) fusing the grown nanotubes to form a three dimensional    nanostructure;-   (3) deposition of a catalyst and growth of nanotubes on or within    the three-dimensional nanostructure;-   (4) repeating (2) to (3) for a time sufficient to achieve a desired    thickness, density or property for the three-dimensional    nanostructure.

In this type of method, growing of the carbon nanotubes comprises acatalytic CVD process. The process to grow carbon nanotubes typicallyrequires carbon containing vapor to be in presence of catalystnanoparticles at a temperature sufficient to produce carbon nanotubes.

The method of applying the catalyst in (3) comprises the Chemical VaporDeposition or Physical Vapor Deposition of catalyst.

The process of applying the catalyst may comprise depositing ametal-organic catalyst layer, such as ferrocene or an iron pentacarbonylcontaining layer.

In addition to the previously described multi-step recycling method, acontinuous method of making a three-dimensional nanostructure material,may be used. This type of method comprises growing carbon nanotubes, insitu, and fusing the grown carbon nanotubes substantially simultaneouslywith the growing process. In one embodiment, annealing may also beperformed simultaneous with or prior to fusing. As before, annealing maybe performed using a thermal or electrical process.

In any of the previously described methods, the carbon nanotubes may begrown with a gas chosen from but not limited to: ethanol, carbonmonoxide, xylene, acetylene, and methane. Growth of the carbon nanotubesmay be enhanced/improved by depositing a metal-organic catalyst layer,such as ferrocene or iron pentacarbonyl.

Non-limiting examples of the methods used to the manufacture thenanostructure materials described herein include an organic solventevaporation process, a geometric weave process, a vacuum filtrationprocess, and a nanostructure polymerization process. Each of theseprocesses, including those described in more detail below, can create ananostructure with nanomaterials embedded on them or composed of them.

To enhance its structural support and binding to other entities, theentire nanostructured material can be coated with the previouslymentioned metals, plastics, or ceramics. In addition, structuralintegrity of the nanostrutured material can be enhance by chemical,electrical, thermal, or mechanical treatment or any combination thereof. In non-limiting embodiments, mechanical treatment could involverolling the material under pressure, electrical treatment could beperformed for a time sufficient to perform electro migration, andthermal treatment could be performed for a time sufficient to reachdiffusion bonding).

In any of the above-described methods, the starting carbon nanotubesgenerally contain residual iron particles or other catalytic particlesthat remain after production of the nanotubes. In certain embodiments,it is desired to wash the carbon nanotubes with a strong oxidizing agentsuch as acids and/or peroxides or combinations there of before forming ananostructured material. Upon washing with a strong oxidizing agent, theiron generally found in the carbon nanotubes is oxidized to Fe++ andFe+++. In addition, acid washing has the benefit of removing amorphouscarbon which interferes with the surface chemistry of the nanotube.

It is also thought that this acid washing procedure contributes to thehigh degree of hydrophilicity of these functionalized carbon nanotubesand the resulting carbon nanostructured material. The washed carbonnanotubes are generally fabricated into a nanostructured material usingone of the following processes. It is noted that any one of thefollowing processes, as well as those described in the followingsections, can be used to create a nanostructured material describedherein, whether multi or monolayered.

Organic Solvent Evaporation Process

In the Organic Solvent Evaporation Process, a nanostructure material,such as a fluid sterilization membrane, can be made by bondingnanomaterials with an adhesive. Examples of fluid sterilizationmembranes that can be made in accordance with method described hereincan be found in co-pending U.S. patent application Ser. No. 10/794,056,filed Mar. 8, 2004, which is herein incorporated by reference. Examplesof adhesives are chemical adhesives, such as glue.

According to this process, carbon nanotubes can be mixed with a organicsolvent, such as methanol, ethanol, isopropanol or xylene. In oneembodiment, this dispersion is next placed in an ultrasonic bath for atime sufficient to exfoliate the carbon nanotubes. The resultingdispersion is next poured onto porous substrate to remove organicsolvent. Additionally, other polymers or polymeric materials may beadded to the organic solvent to enhance the resulting said nanostruturedmaterials physical or mechanical properties.

Deposition Process

In this process, a nanostructured material can be made by vacuumdeposition of carbon nanotube dispersions to lay down layers of carbonnanotubes on at least one substrate. Ultrasonication using a “Branson900B” Model at 80% to 100% power may be used to aid in dispersing and/ordeagglomerating carbon nanotubes during deposition.

An envisioned process of the deposition method comprises placing carbonnanotubes in a suitable organic solvent or water and ultrasonicatingusing a “Branson 900B” Model at 80% to 100% power for a time sufficientto disperse the carbon nanotubes during deposition. The solution can beplaced in a vacuum filtration device equipped with ultrasonication tofurther ensure that the carbon nanotubes are deagglomerated.

Fabrication of One Boron Carbide Nanostructure Material

In one embodiment, blast mitigation materials comprising thenanostructured material described herein and boron carbide can befabricated. For example, a multilayer ballistic material can be made byfirst starting with multi-walled carbon nanotubes up to 1000 microns inlength and 50 nm in width. As used in this embodiment, “multi-walled”means up to 25 walls. This morphology of carbon nanotube can be mixed ina 1:1 ratio with a sacrificial material, such a calcium oxide supportfibers 1 mm in length and 100 nm in width.

Different boron sources, such as boron carbonyl or diborane, may be usedto coat the carbon nanotube/calcium oxide mixture using a chemical vapordeposition (CVD) process. For example, when boron carbonyl is used, aCVD temperature ranging from 600° C. to 750° C., such as 700° C. can beused. Once the nanotubes have been coated with boron then the boroncarbide can be formed by raising the temperature to 1100° C. Whendiborane is used, a higher CVD temperature, such as one ranging from900° C. to 1200° C., such as 1100° C. can be used. In either case, a CVDpressure of 100 mT is generally sufficient to treat the carbon nanotubesand develop the desired boron carbide coating.

Other methods of deposition boron to form a boron carbide layer includesphysical vapor deposition (PVD) or boron implantation, typically at 120keV to 1.4 MeV (100 to 1,000 atoms per square nanometer). Ionimplantation is generally used when surface implantation is desired.

When relevant, crosslinking of the nanostructured material can takeplace via electrical, chemical or thermal processing. For example, ane-beam process can be used to generate an energy flux of 130 keV (10particles/nanometer), which should be sufficient for crosslinking thenanostructured material.

Any of the above process can be used in either a batch or continuousmethod of making a boron carbide/carbon nanotube nanostructuredmaterial. When used in a continuous process, it is envisioned that thespeed of production can approach or even exceed the industry standard of100 feet per minute.

Additional general variables that may be used to fabricate a boroncarbide nanostructured material described herein is shown in thefollowing table.

TABLE 1 Variables Used in Nanostructured Fabrication Method MethodElement Range Choices Choice Variable Low High Starting Morphology ofcarbon Length 1 um 1000 km Material fibers Width (nW) 10 nm 10 um # ofwalls 10 1000 Choice and Composition Ceramic Metal morphology of supportLength 10 um 100 m fibers Width sW sW = 2x(nW) sW = 10x(nW) SacrificialYes/No Ratio of cnt to support Cnt:support 100:1 1:100 CVD TemperaturePure Boron Vapor 1900° C. 2500° C. Boron Carbonyl 600° C. 750° C.Diborane 900° C. 1200° C. CVD Pressure Boron Carbonyl 1 mT 600 mT (*)Diborane 1 mT 600 mT (*) CVD Exposure time Diborane 10 min 1 hr BoronCarbonyl 10 min 1 hr PVD Deposition Deposition layer 1 atomic 5,000,000atomic thickness Layer Layers Temperature Nanostructured 25° C. 500° C.Material temperature Boron Implantation Energy-Flux 80 keV-1 fx 200keV-1000 fx Process Batch Size of batch 1 (mm)³ 100 (m)³ ChoicesContinuous Reel to Speed of 0.01 f/m 1000 f/m Reel productionCrosslinking Linear E-Beam Energy-flux 0.01 f/m 1000 f/mwherein,

-   cnt=Carbon nanotubes-   fx=particles/nanometer-   keV=kilo electron volts-   f/m=feet per minute-   (*)=molecular flow-   mT=mlTorr

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

Unless otherwise indicated, all numbers expressing quantities ofingredients, reaction conditions, and so forth used in the specificationand claims are to be understood as being modified in all instances bythe term “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by the present invention.

1. A nanostructured material comprising carbon nanotubes fused togetherto form a three-dimensional structure.
 2. The nanostructured material ofclaim 1, wherein said carbon nanotubes have a scrolled tubular ornon-tubular nano-structure of carbon rings.
 3. The nanostructuredmaterial of claim 2, wherein said carbon nanotubes having a scrolledtubular or non-tubular nano-structure of carbon rings are single-walled,multi-walled, nanoscrolled or combinations thereof.
 4. Thenanostructured material of claim 2, wherein said carbon nanotubes havinga scrolled tubular or non-tubular nano-structure have a morphologychosen from nanohorns, cylinders, nanospirals, dendrites, spidernanotube structures, Y-junction nanotubes, and bamboo morphology.
 5. Thenanostructured material of claim 1, wherein said carbon nanotubescomprise impregnated, functionalized, irradiated, doped, charged,coated, and bonded to one another or bound with other materials, andcombinations thereof.
 6. The nanostructured material of claim 1, whereinsaid three-dimensional structure further comprises at least one materialchosen from polymers, ceramics, and metals.
 7. The nanostructuredmaterial of claim 6, wherein said polymers, ceramics, and metals are ina form chosen from fibers, beads, particles, wires, sheets, foils, andcombinations thereof.
 8. The nanostructured material of claim 6, whereinsaid polymers are chosen from single or multi-component polymers.
 9. Thenanostructured material of claim 8, wherein said single ormulti-component polymers are chosen from nylon, polyurethane, acrylic,methacrylic, polycarbonate, epoxy, silicone rubbers, natural rubbers,synthetic rubbers, vulcanized rubbers, polystyrene, aramid,polyethylene, ultra-high-molecular weight polyethylene, high-densitypolyethylene (HDPE), low-density polyethylene (LDPE),poly(p-fenyl-2,6-benzobisoxazol), polypropylene, polychloroprene,polyimide, polyamide, polyacrylonitrile, polyhydroaminoester, polyester(polyethylene terephthalate), polybutylene terephthalate,poly-paraphylene terephtalamide, polyester ester ketene, vitonfluoroelastomer, polytetrafluoroethylene, and polyvinylchloride.
 10. Thenanostructured material of claim 6, wherein said ceramics are chosenfrom at least one of the following: boron carbide, boron nitride, boronoxide, boron phosphate, beryllium oxide, spinel, garnet, lanthanumfluoride, calcium fluoride, silicon carbide, carbon and its allotropes,silicon oxide, glass, quartz, aluminum oxide, aluminum nitride,zirconium oxide, zirconium carbide, zirconium boride, zirconium nitrite,hafnium boride, thorium oxide, yttrium oxide, magnesium oxide,phosphorus oxide, cordierite, mullite, silicon nitride, ferrite,sapphire, steatite, titanium carbide, titanium nitride, titanium boride,and combinations thereof.
 11. The nanostructured material of claim 6,wherein said metals are chosen from at least one of the following:aluminum, boron, copper, cobalt, gold, platinum, silicon, steel,titanium, rhodium, indium, iron, palladium, germanium, tin, lead,tungsten, niobium, molybdenum, nickel, silver, zirconium, yttrium, andalloys thereof.
 12. The nanostructured material of claim 6, wherein atleast one of said polymers, ceramics, and metals are grown, deposited,and/or implanted on the surface or in the interior of the carbonnanotubes to form polymer containing particles or layers, ceramiccontaining particles or layers, metal containing particles or layers, ora combination of any or all of these particles or layers.
 13. Thenanostructured material of claim 12, wherein said at least one ceramiccontaining layers or particles comprise boron carbide.
 14. Thenanostructured material of claim 1, wherein said material comprises 5, 6and 7-membered carbon rings at the intersection of two or more carbonnanotubes.
 15. The nanostructured material of claim 1, wherein saidstructure has a density ranging from 1 picogram/cm³ to 20 g/cm³.
 16. Anarticle comprising the nanostructured material of claim
 1. 17. Thearticle of claim 16, which is in the form of a fabric, ballisticmaterial, structural support, mechanical actuator, heat sink, thermalconductor or insulator, or a membrane for fluid purification.
 18. Thearticle of claim 17, wherein said thermal insulator comprises a blanket,tent, clothing, or sleeping bag.
 19. A ballistic cloth comprising ananostructured material comprising carbon nanotubes and at least onematerial chosen from a polymer, ceramic, and metal fused together toform a three-dimensional structure. 20-49. (canceled)
 50. A multi-steprecycling method of making a three-dimensional nanostructure, saidmethod comprising (1) growing carbon nanotubes in a reactor; (2) fusingthe grown nanotubes to form a three dimensional nanostructure; (3)applying a catalyst and growing nanotubes on or within thethree-dimensional nanostructure; (4) repeating (2) to (3) for a timesufficient to achieve a desired thickness or property for saidthree-dimensional nanostructure. 51-58. (canceled)